It looks like a great harness you've got there but I suspect that the little legs aren't making a good contact with the socket. Try making a plug-in board - you'll use it over and over.

When it comes time to attach it to protoboard I usually bend the little pins down a bit and use them to locate to the card solidly. I tack them, then solder the tabs at the sides to lock the holder in place. As you might expect really.

Thank you, that sure was helpful, but my first thought that it might be really damn simple to connect a card to the arduino is more or less destroyed. If i look at your pics, especially those close-ups of your shield makes me realise that i need more than a few pins and cables to connect the card to the arduino.. do you have a schemata of what is connected what way to what else? I ask becuase this looks much different to what i have seen in the first post of this thread... and i am quite confused now ><

Believe me, Mike, I calculated the odds of this succeeding against the odds I was doing something incredibly stupid[ch8230] and I went ahead

I had to 'fill up' my data.csv file with junk data so that it was bigger than 512 bytes before it would write anything. One of the sketches which was presented in this post recommended at least 15kb file size; having a data.txt file of 0 bytes would lead to sectorsavailable() returning 0 & there being not enough space in the file to write any data. As I understand it, you will only be able to write data to the file up until the original file size; more data will NOT increase the file size as required, it will just fail to write to the file. (I think - sirmorris will correct me if this is wrong!

Try making your file larger... fill it with anything you like as it will be overwritten anyway. You could even take any other old .txt file & rename it if you wanted, saves the hassle of making stuff up!

if you just want to log data (and not necessarily read it) i have an sdlogging library that saves to fat16 formatted SD cards. i use it to log GPS & sensor data: http://www.ladyada.net/make/gpsshield/download.html

Is anybody using this library? It overcomes some of the limitations of the libraries everyone is discussing here.

I came across this one too, which supports fat32 and sdhc: http://code.google.com/p/wavehc/

I have played arround with LadyAdas code for a while, but as i was not able to set up the wiring right for it i could not really test it.. but what i noticed was quite a big overhead.. if i remember right it took quite a bunch of space on the arduino.. yet it seemed really good from its limitation/options.

Believe me, Mike, I calculated the odds of this succeeding against the odds I was doing something incredibly stupid[ch8230] and I went ahead

The wiring should be the same for the ladyada code - the arduino's hardware SPI support works on a certain set of pins only. I tried my code out on a ladyada GPS board at dorkbot London a few weekends ago and it worked without modification.

As for using the ladyada code 'to get around the limitations of uFat' - well we're going full circle uFat is my way of getting around the limitations of having very little RAM and flash left after using the full FAT library..!

If your sketch is quite small and you can use the more fully featured library then I would suggest doing so as it makes your life really easy! uFat was designed for situations when this isn't quite the case I've traded simplicity for RAM. A full sketch of uFat, MMC & deviceprint will use under 5k. You have to make compromises - this is a classic trade-off!

The DevicePrint code will work with anyone's library. You do need the arduino IDE version 0012/0013 though.